1. Technical Field
The present invention relates to a memory management method, and particularly relates to a memory management method for managing a rewritable non-volatile memory module having a plurality of devices and a memory control circuit unit and a memory storage apparatus using the same.
2. Description of Related Art
The growth of digital cameras, mobile phones, and MP3 players has been rapid in recent years. Consequently, the consumers' demand for storage media has increased tremendously. Since rewritable non-volatile memory has the advantages of being non-volatile, saving power, having a smaller volume, no mechanical structure, and quick reading/writing speed, the rewritable non-volatile memory is most suitable for portable electronic products, such as notebook computers. A solid state disk is a memory storage apparatus using flash memory as a storage medium. For these reasons, flash memory has become a thriving part of the electronic industries.
Generally speaking, when a file is being written to a rewritable non-volatile memory module, file system data (e.g., file allocation table, FAT) and user data (e.g., text data, image data, etc., of the user) are written to a solid state disk. Since reading and writing frequencies of the file system data are relatively higher than reading and writing frequencies of the user data, frequently updating the file system data may result in rapid increase in wear value of the physical erasing units corresponding to the file system data and the device that the physical erasing units belong to. Thus, the wear value of the physical erasing units storing the file system data and the device that the physical erasing units storing the file system data belong to may be higher than the wear value of the physical erasing unit not storing the file system data and the device that the physical erasing units not storing the file system data belong to, making the wear values of devices in the rewritable non-volatile memory module highly different. Accordingly, how to level the wear values of the rewritable non-volatile memory module to prevent the whole rewritable non-volatile memory module from being damaged due to a specific overly worn device is certainly an issue that the researchers in this field should work on.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.